How long before Labour asks whether David Shearer is the solution or the problem? If the results of today's Fairfax Media-Ipsos poll are a precursor to the next election, the news is all bad for Labour - and not just because the poll has it shedding support, though that is bad enough.

OPINION:
But because it reverses a trend that had Labour slowly clawing into contention.

What changed? To lean on a cliche, the economy, stupid.

The poll shows a sudden surge in people who think the country is on the right track - a combination of the wealth effect of a rise in house prices, particularly in Auckland, a drop in the number of jobless, better growth figures and a feeling that there is light at the end of the tunnel for the economy.

There are plenty of niggles with the Government but they are just that - niggles.

None has taken on the tsunami-like proportions of the nanny state backlash that swept Labour out of office.

And with optimism on the rebound, National's message at the election in 2014 looks like an increasingly potent one - we've taken our medicine, done the hard yards, and we're starting to reap the gains. Why put that all at risk?

But something else may also be changing. Mr Shearer may be morphing from Mr Invisible to something worse in voters' eyes. Mr Negative.

Labour has taken bold steps in policy, including its affordable housing plan, reforming the power market, a capital gains tax and raising the pension age.

Admittedly, there is a reason why policies like the capital gains tax and raising the pension age haven't been tried before. They are deeply unpopular. But if the gambit was to make Labour look like a government in waiting, it has not worked.

Labour MPs' sights are not trained on Mr Shearer yet.

But there is always a tipping point. And if the trend continues, Labour MPs must be wondering what to do when they reach it.